Centrifugal clutch with removable cantilever spring



T. L. FAWICK Jan. 20, 1953 Fild July 8, 1949 2 SHEETS-SHEET 1 IN VEN TOR. THOMAS L. FAWICK W l m 3 Um u g a 6 U i fl u Tm J w m w m M a m a M Quill Tlih 6w 4 Fix Jan. 20, 1953 T. FAWICK 7 2,626,034

CENTRIFUGAL CLUTCH WITH REMOVABLE CANTILEVER SPRING Filed July 8. 1949 2 SHEETSSHEET 2 INVENTOR. THOMAS L- FAWICK MM 187. EQZA 'ATTORNEV Patented Jan. 20, 1953 OENTRIFUGAL CLUTCH WITHIREMOVABLEI CANTILEVER SPRING Thomas L. Fawick, Cleveland, Ohio, assignor'to;

The Fawick Airflex Company,lnc ya-corpora tion of Indiana Application July 8, 1949," Serial No. 103,588

4 Claims.

This invention relates to centrifugal clutches and especiallyclutches.suchasare described and claimed in my U.'"S.'P'atent No. 2,375,909, granted May/15, 1945;

The chief objects of the present invention" areto provide;improved"springgameans: opposed to the centrifugal force of frictional drive members andespecially to provide for ease and economy of assembly j and disassembly and substitution, of parts;

or "the accompanying d awings:

Fig.1 an axial section of,a. c1utch embodying myinyention in its preferred form, on line. ,l-J f;.F -;,2 -i

Fig.52 iisya transverse section, on line 2+2-fof Fig. 1.

The embodimentwhere shown-comprises a bellshapeddriven member I0 secured upon the driven shaft II and having a frictional inner face 12 for engagement by a set of centrifugal structures pivotally mounted upon a driving member l3.

Thepivotal support foreachof the centrifugal structure comprises a pin or stud l4 formed with a tapered base portion ll seated in a tapered hole extending through the driving member [0 and held therein by a nut M on the pin. The projecting stud portion of each pin has mounted thereon an annular cushioning assembly comprising an outer metal shell l5, an inner metal shell I6 and an annular body or bushing l1 composed of natural or synthetic rubber which occupies the annular space between the metal members and preferably resists, yieldably, relative angular movement of the two.

This rubber bushing assembly can be of either the compression type, in which the rubber memher is vulcanized to the inner metal member and forced axially into the outer shell, so that its axial recoil maintains it under strong radial compression, or it can be of the axially-clamped type, each of those types of rubber bushing assemblies being well known in the rubber-bushing art, but preferably, for economy of manufacture, it is of the type in which the rubber member is given strong adhesion to the inner and outer metal members by being mold-vulcanized in place between them under high pressure, with the use of a suitable adhesive, in accordance with practice well known in the art.

The rubber-bushing assembly as described is held upon the stud by a snap-ring I8 mounted in an annulargroove in the outer end portion of the stud. The fit of the inner metal member IS on the Stud [4, and the fit of the outer metal member in the hub l! of a centrifugal member [9, can be a strong, frictional fit, so that rotative movement of the member l9 induced bycentrifu-i gal force will be yieldingly resisted by' torsional strains in the rubber, or the springs hereinafter described:icanbev adapted to provide all of the necessaryz yielding. force opposed to the centrifugal force of the pivoted structures, in l which caselitdspermissible-for the innermetal member I lifiof 2the: bushing assembly/toberotatable upon thee-stud: l4, alignment being maintained by spring latching-means such as the snap ring l8 coactingrwithwhe,member: It "and by a strong fricti nal:months-outer shell 5 ;in; the. hub; 199'.

Eachzof :the ecentrif gal m mb rs i 9 is; fac d, withbrakerlining material; l9 for engagement withgthe, face- I2;of -the driven member [9. The hinge axis of eachof-thecentrifugal members 1513,12 2; substantial distance radially inward from the-face;|-2: of the-driven-member-and because of this aj-desirableamount, of self-energizing effect is- .provided when the direction of drive is counv terclockwise, Fig. 2.

The improyed spring-means, heretofore referred to as being opposedto outward movement of the pivoted centrifugal members, comprises a set of flat springs 20, 20 for the centrifugal members l9, l9 respectively.

Each spring 20 bears, at a position near its middle, against the radially inner side of a stud 2| press-fitted in and projecting axially from the driving member l3. At the inner corner of its outer end the member It has secured thereto by a pair of cap-screws 22, 22 a spring-seat stamping 23 having a channel or U-shaped portion for receiving an end portion of the spring and holding it against lateral movement and against radially inward movement with relation to the member l9 while permitting it to have lengthwise sliding movement on the floor of the channel.

An identical stamping, 23, for the other end of the spring, is similarly secured to the hub portion l9 of the centrifugal member l9.

Each of the studs 2| serves as an abutment for straining of the spring and also as a stop for the centrifugal member I9 in its inward, clutchdisengaging, movement, as is shown clearly in Fig. 2.

Each of the stampings 23, 23 is so shaped and proportioned that its spring-seating channel portion is at a distance radially inward from the adjacent face of the member is and therewith defines an open space 23 of slightly greater radial dimension than the thickness of the end portion of the spring. This permits placement and removal of the spring by suitably bending it and passing it axially into or out of its working position. In mounting the spring its middle portion can be engaged with and moved along the stud 2| for a substantial distance before its ends will overlie their sockets in the members 23, the stud 2| being of suitable length to provide that advantage, for easy manual holding of the spring in a somewhat flattened condition. When the spring has been moved a suitable distance along the stud and is then released its end portions come to rest in their respective sockets, with the spring still under appropriate pre-loading strain for performance of its function.

The construction as described also is such that the several pivotal structures, with or without the springs, can be individually preassembled and readily mounted upon, or removed from, the studs 14.

Modifications are possible without departure from the scope of the invention as defined by the appended claims.

I claim:

1. A centrifugal clutch comprising a driven member having an internal frictional-engagement face, a driving member, a set of centrifugal members pivoted on said driving member for swinging movement thereon toward and from said engagement face, a retracting spring of the cantilever type for each of said centrifugal members, the driving member having a seat for the middle portion of each of the springs and each centrifugal member having two seats at different distances from its pivotal axis for the respective end portions of its spring, said seats for each spring having such clearances as to permit the spring when deformed by bending strain to be passed axially of the assembly into approximately final position and to assume final position in relation to its seats upon relaxing of the strain, the seats for each spring comprising means automatically interlocking with a side edge of the spring, upon such relaxing, to prevent axial displacement of the spring.

2. A centrifugal clutch as defined in claim 1 in which cushioning material having substantially the resilient deformability of vulcanized soft-rubber is so interposed between the driving member and each of the centrifugal members as to cushion the centrifugal member against its centrifugal force and against its sustension of the driving torque.

3. A centrifugal clutch as defined in claim 1 in which each centrifugal member is pivotally mounted on a stud projecting from the driving member and in which a bushing having substantially the resilient deformability of vulcanized soft-rubber is interposed between each of the studs and the respective centrifugal member.

4. A clutch as defined in claim 3 in which the recited bushing is freely rotatable upon the recited stud in the maintaining of balance between the centrifugal force and the force of the spring.

THOMAS L. FAWICK.

REFERENCES CITED The following references are of record in the file of this patent: V

UNITED STATES PATENTS Number Name Date 919,523 Barker Apr. 27, 1909 1,870,649 Rawson Aug. 9, 1932 2,005,250 Wemp June 18, 1935 2,166,165 Linderman July 18, 1939 2,375,909 Fawick May 15, 1945 2,428,552 Butler Oct. '7, 1947 2,471,747 Hinden et al May 31, 1949 2,534,426 Eason Dec. 19, 1950 FOREIGN PATENTS Number Country Date 273,918 Great Britain July 14, 1927 410,252 Great Britain May 17, 1934 579,385 Germany June 8, 1933 2,236 Netherland Nov. 1, 1917 

